Far-IR Photoconductor Array to Go into Space

Scientists from the Communications Research Laboratory in Tokyo have developed what they believe may be the first direct hybrid two-dimensional far-IR detector array. As reported in the April 20 issue of Applied Optics, the Ge:Ga array will be installed on the Japanese IR satellite Astro-F, which is scheduled for launch in 2004 by the Institute of Space and Astronautical Science.

Ge:Ga photoconductor arrays that capture 2-D terahertz images are used in space observation. Because the photoconductor must be cooled below 3 K for low-noise characteristics, the researchers needed a monolithic Ge:Ga photoconductor array, cryogenic readout circuits and a means of connecting the two. They said that the only drawback detected was 5 percent crosstalk between pixels, although this is within acceptable levels.